1. Field
Apparatuses and methods consistent with exemplary embodiments relate to optical filters and optical measuring devices employing the same, and more particularly, to optical filters designed to have a narrow linewidth of light and change a wavelength being filtered during a manufacturing process and optical measuring devices employing the optical filters, which are capable of measuring intensity of light filtered for each pixel.
2. Description of the Related Art
In general, optical spectrum analysis is used to measure and analyze physical and chemical states of an object. This analysis technique is used in various industrial fields such as optics, medicine, chemistry, and ocean engineering.
In optical spectrum analysis, optical spectroscopy is used to split light into several wavelength ranges and measure intensity of the light at each wavelength to analyze the spectrum of the light. The optical spectroscopy is classified into a light scattering technique in which incident light is transmitted through a periodic crystal structure and scattered in different directions at each wavelength and a filtering technique in which only light of a specific wavelength is transmitted through an optical filter.
In the light scattering technique, an optical sensor may be fixed, and a crystal structure may rotate so as to measure light of different wavelengths that reach the optical sensor. Alternatively, a crystal structure may be fixed, and a plurality of optical sensors may be located at different positions so that each optical sensor measures light of a particular wavelength.
In the filtering technique, an optical filter may be a metal mesh filter, a dichroic filter using a thin film, a filter using a Fabry-Perot interferometer, or a pigment type color filter manufactured by coating a substrate with a pigment-dispersed photoresist solution and patterning the substrate.
In recent years, optical spectrum analysis has been used extensively in a variety of applications, beyond laboratory analysis, including everyday-life items such as portable and wearable devices. Thus, there is an increasing need for a small-volume optical filter to filter a very narrow linewidth wavelength region. Furthermore, as optical filters have been used in a wide variety of applications, a technique of easily changing a wavelength being filtered by an optical filter during a manufacturing process has become an economically important issue. Furthermore, much attention is being directed toward miniaturization of a device for measuring an optical spectrum by using an optical filter.